The present invention relates to spinal surgery, namely, the fusion of adjacent intervertebral bodies.
Back pain can be caused by many different maladies, not the least of which are problems that directly impact the intervertebral disks of the spine. Typical disc issues include, inter alia, degeneration, bulging, herniation, thinning and abnormal movement. One method of treatment of such disc problems that has been widely utilized in the field of spinal surgery is a spinal fusion procedure, whereby an affected disc is removed, and the adjacent vertebral bodies are fused together. Currently, implants, pedicle screws and the like are utilized to facilitate the fusion.
One type of implant that has recently gained favor are so-called stand-alone cages. These intervertebral implants effectuate spinal fusion without the need for secondary fixation through the use of, for instance, pedicle screws. One example of such a stand-alone cage is disclosed in U.S. Pat. No. 8,349,015 (“the '015 Patent”), the disclosure of which is hereby incorporated by reference herein. In the '015 Patent, a PEEK body is surrounded by a metallic jacket and anchors are inserted through both superior and inferior surfaces the implant and into the upper and lower adjacent vertebral bodies respectively.
Although stand-alone cages are successful in effectuating spine fusion, intraoperative and postoperative visualization of the implants remains a challenge. This is especially true given the advent of polymeric implants that are constructed of PEEK and therefore do not show up when conducting standard imaging processes. Nonetheless, surgeons typically need to verify proper implant position, location and rotation.
It has been known for some time to imbed radiopaque markers in polymeric bodies, so that at least the markers show up on X-rays or other images taken of the implant. Surgeon can compare the positions of the markers to each other and/or the anatomical features of the spine to determine whether the implant is properly placed. However, implants with such a design require additional manufacturing efforts (i.e., imbedding the markers in the polymeric) that are costly, time consuming and may adversely affect the structural integrity of the implants.
Therefore, there exists a need for an improved spinal implant that overcomes the aforementioned drawbacks.